A study for hydrogen evolution on Pt–MnCu electrocatalyst

Abstract

Electrocatalysts to be used in electrolysis, which is one of the hydrogen production methods, are very important. The development of electrocatalysts is related to the internal structure of combinated more than one metal. In the present work, the graphite substrate is coated with manganez (C/Mn), manganez-copper (C/MnCu) and this surface is modified with platinum nanoparticles (C/MnCu–Pt) using the electrodeposition method. Prepared electrocatalysts are used for characterization, hydrogen evolution reaction (HER) and stability using cyclic voltammetry (CV), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), cathodic current-potential curves, electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA). Hydrogen gas is measured in a basic environment by establishing an experimental electrolysis setup on these electrocatalysts. Results showed that binary MnCu enhances the characteristic current density of Tafel curves, reduces the polarization resistance and enhances the hydrogen gas volume compared to graphite substrate and single Mn coating. Apart from that, much more effective results are obtained on the C/MnCu–Pt electrocatalyst. Namely, a very high exchange current density (io = 5.50 mA cm−2), a very low polarization resistance (3.2 Ω cm2) and a very low overpotential (50 mV) at 10 mA cm−2 are obtained on the C/MnCu–Pt electrocatalyst. In addition to high performance, C/MnCu–Pt electrocatalyst exhibits good stability in alkaline medium.